Mercury - Quicksilver 8M0204728 NGK BPF5F Spark Plug (Pack of 10) Ignition System Trivalent Metal Finish 8M0204728. Overview. There's something reassuring about an engine that fires up instantly - no hesitation, no stumble, just that clean, confident spark that tells you the day's off to a good start. Every boater knows that feeling, and the right spark plug plays a bigger role in it than most people think. This Mercury Marine part delivers that kind of trust. Whether you're heading out before s